An electric test of a plate-like device under test provided with a plurality of electrodes such as a semiconductor device is generally conducted, using an electric connecting apparatus such as a probe card, a probe unit, a probe block and the like.
As one of such electric connecting apparatus, there is a type provided with a cylindrical elastic body and a first and a second contact pins disposed in a through hole portion of this elastic body (Patent Document 1).
Patent Document 1:
Japanese Patent Appln. Public Disclosure No. 2001-250600
In this conventional apparatus, the first and second pins are disposed to adjoin each other in the axial direction of the through hole portion and come in contact in an inclined plane inclined to the axis of the through hole portion, and the apparatus is further provided with a flange-like base, which is in contact with a face of an elastic plate, at an end portion on the opposite side to the inclined plane.
In this conventional apparatus, when energizing force is exerted in a direction to make the first and second pins approach each other, both pins displace along the inclined plane with which they are in contact to compress and deform the elastic body in the axial direction of the through hole, deforming the through hole in a direction to expand, and when the energizing force is no longer exerted on the first and second pins, the pins are restored to their initial state by the elastic force of the elastic body.
In the above-mentioned conventional electrical connecting apparatus, however, though the elastic body is elastically deformed in the axial direction when the energizing force is exerted on the first and second pins, a part which compresses and deforms the elastic body in its axial direction is merely the flange-like base. Therefore, the force compressing and deforming the elastic body in its axial direction is greatly counteracted by the force expanding the through hole, so that the amount of compression and deformation of the elastic body due to the energizing force is remarkably small. Also, the force to compress and deform the elastic body in its axial direction falls short.
Also, in the foregoing conventional electrical connecting apparatus, when the energizing force is no longer exerted on the first and second pins, the force which has compressed and deformed the elastic body in the direction to expand the through hole acts as frictional resistance force to the first pin which tends to return to the axial direction of the through hole. For this reason, restoring force acting on the first pin due to the force which has compressed and deformed the elastic body in the axial direction of the through hole is greatly counteracted by the restoring force acting on the first pin due to the force which has expanded the through hole.
As a result, in the conventional electrical connecting apparatus, when the energizing force no longer acts on the first and second pins, the restoring force for returning the first and second pins to their initial states, more particularly, the force for displacing the first pin in a direction to be apart from the second pin falls short.